The process defined herein, for plant scale production of cement with mechanical compounding is related in part to the process described in U.S. Pat. No. 3,066,031, entitled "Cementitious Material and Method of Preparation Thereof," issued Nov. 27, 1962 to Charles J. Schifferle and assigned to Joseph J. Coney. The process described therein was laboratory developed under the initiative and direction of Joseph J. Coney. It has been demonstrated, as described in said patent which is incorporated herein by reference, that a cementitious material can be produced without the expensive kiln operation of clinkering to obtain a high strength cement of the quality of Portland cement. Granular raw materials as specified were mixed, dried if necessary, and were attrition ground to 200 mesh or less. The grinding was continued until samples that are extracted and hydrated indicate, by measurement of the heat of hydration, that the constituent calcium oxide has reacted with the other metallic oxides of the mixture to the degree desired. It was thought that the prolonged attrition grinding caused the formation of the cementitious material.
While the process described in the Schifferle patent was adequate to demonstrate operability of the concept, it was inefficient and inapplicable to a production plant operation by simple scaling. The attrition grinding operation was difficult to regulate from the standpoint of quality control, and the ability to control diminished with scaling increases. Determination of appropriate product quality was primarily by periodic sampling. Furthermore, the energy expended in the prolonged grinding operation was detrimental to the overall cost justification of the process. It was subsequently discovered that it was not attrition grinding as a whole that caused the cementitious composition to form but rather facet or side effect of the grinding process that actually was the cause.
These and other difficulties made application of the laboratory process to a production plan unattractive until the development of the substantial improvements described herein wherein the particular cause of the formation process was defined and specified.